The present description relates to apparatus for supplying groups of articles, each including a predetermined number of the articles, to a station which is constituted, for example, by a removal station, at which a unit, such as, for example, an industrial robot or manipulator, operates.
The requirement to provide apparatus of this type is experienced, for example, in automatic packaging lines, such as lines for the automatic packaging of food products.
In these lines, the "unwrapped" products (that is without packaging) are sent in a substantially continuous flow to packaging machines which wrap them in a wrapper, for example of the type currently known as a "flow pack".
These packages, with the products inside them, are then collected in groups for insertion in containers such as boxes or flow packs of larger dimensions.
Their transfer to these further containers can be achieved by means of removal units (for example ejectors or manipulators, which may also take the form of robots or automatons) which can remove one or more groups of articles intermittently.
In general, it is difficult to operate these removal units with a flow of articles in continuous movement, particularly when a fast rate of working is required. The removal unit (one is thinking, for example, of an ejector unit or a manipulator) usually has a finite operating time which does not reconcile well with the fact that the products which are to be removed are in continuous movement. It may then be necessary to make the removal unit capable, to a certain extent, of following the movement of the products which are presented at the removal station. This, however, makes the design and production of such a unit to achieve reliable operation very complex, to the extent that its use at fast working rates, is, in fact, prohibitive.
The problem is made even more complicated by the fact that the articles in the flow of products fed to the removal station (for example the flow of articles discharged from a packaging station of the flow-pack type) may not be uniformly spaced, partly because of the discarding of incorrectly-packaged articles and partly because of chains of articles which are packaged correctly individually but which are connected together undesirably as a result of their imperfect separation at the output of the packaging station.
One is thus dealing, in the terms used in the present description and in the claims which follow, with a "substantially, but not necessarily continuous" flow of articles.